KR101066807B1 - Data recording/reproduction for write-once discs - Google Patents

Abstract

A file system for using metadata partitions instead of a VAT for write-once discs is enabled, which is enabled by a pseudo-overwrite method, which allows for multiple tracks, in particular for metadata and file data. Tracks are provided. When the present invention is applied to a drive device supporting a pseudo-overwrite medium, the file system distinguishes data for overwriting from data to be added (S1701). When data is newly recorded in the logical sector, the driving apparatus writes the data in the physical sector to which the logical sector corresponds (S1704). When the data to be overwritten is data stored in the logical sector, the data is recorded in another unrecorded physical sector in the volume space (S1704), and remapping information is recorded (S1705). The remapping information specifies the original address of the physical sector and the remapping address of the physical sector in which data is recorded.

Write-once discs, VAT, metadata, partitions, tracks, data, volume space, remapping information, physical sectors, logical sectors

Description

Data recording / reproduction for write-once discs}

The present invention relates to a write-once-type disc recording method and apparatus using a logical overwritable mechanism and reproducing method and apparatus, and a semiconductor integrated circuit for use in the recording apparatus and / or reproducing apparatus.

The file system for optical disks has made progress through several activities to develop the Universal Storage Technology Association (OSTA) published Universal Disk Format® (UDF) specification.

In the write once type disc, the recording method has been improved from multi-session recording to file-by-file recording using a virtual allocation table (VAT).

On the other hand, in a rewritable disc, the volume and file structure are improved from a structure using non-sequential recording defined in the international standard ECMA 167 to a structure using a metadata partition specified in UDF version 2.5 (hereinafter referred to as UDF 2.5). It became. Advantages of using metadata partitions include improved performance in retrieving metadata such as entries / directories, and increased durability against metadata corruption.

However, metadata partitions cannot be used for data attachment on write-once discs. This is because using metadata partitions with VAT is not allowed in UDF 2.5, especially because of the difficulty in implementing this combination.

Typically, developing new recording methods for write-once discs is also difficult. This is because the physical characteristics of the write-once disc make it difficult to overwrite the data written once. Considering the new recording method needs to be compatible with the computer architecture, the drive device needs to be implemented, and the resources available to consumer electronics, research on the new recording method has been carried out in many ways.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problem and includes the object of providing the advantages of metadata partitioning to data recording applications on a write-once disc.

A method for instructing a drive device having a pseudo-overwrite function to write data to a write-once disc comprising a plurality of tracks according to the present invention comprises: (a) a write request specifying at least data for a file to be recorded; (B) instructing the driving device to read a file entry of a metadata file to obtain a file entry of the metadata, wherein the metadata is generated from the location of the write once disc. Managing a file, (c) obtaining track information indicative of the location of each of the plurality of tracks, and (d) based on the file entry and track information of the metadata, where metadata is next recorded Determining one track from the plurality of tracks; (e) the drive device from the position of the write once disc to the meta Instructing data to be read, obtaining the metadata, (f) obtaining a next recordable address indicating a position where data is next recorded in a track other than the track determined in step (d), wherein the track Is selected from a plurality of tracks, (g) updating the metadata to reflect the recording of the data specified by the write request, (h) a recordable address in a write once disc to the drive device; Instructing to record the data specified by the write request at a location indicated by (i) to the drive device, to the position where the metadata is read in step (e) on the write-once disc. Instructing to record at least a portion of the updated metadata.

In one embodiment of the invention, the method further comprises the steps of: determining whether the next recordable address in the track determined in step (d) is valid, and the next recordable address in the track determined in step (d) is When it is determined that it is not valid, the driving device is instructed to allocate a first track in which metadata is next recorded and a second track in which data is next recorded, and the next recordable address obtained in step (f). Is updated to the next recordable address in the second track.

In one embodiment of the invention, the first and second tracks are assigned within the track selected in step (f).

In one embodiment of the invention, the method instructs the drive device to record at least a portion of the updated metadata of the position indicated by the next recordable address in the first track, wherein the first track Is assigned and at least a portion of the updated metadata is recorded in the first track, and when it is determined that the first track is allocated and at least a portion of the updated metadata is recorded in the first track. Update the entry of metadata to reflect a record of at least a portion of the updated metadata, wherein the drive device is configured to read a file entry of the metadata file in step (b) on the write-once disc. Instructing to record the updated file entry of the metadata file at the location. It includes more.

A system controller for instructing a drive device having a pseudo-overwrite function to write data to a write-once disc including a plurality of tracks, the system controller including a controller for controlling the drive device, The controller may comprise (a) receiving a write request specifying at least data for a file to be written, (b) instructing the drive device to read a file entry of a metadata file to obtain a file entry of the metadata; Managing the file from a location of the write-once disc, (c) acquiring track information indicating a location of each of the plurality of tracks; Based on the file entry and track information of the metadata, one from the plurality of tracks in which the metadata is next recorded Determining a track, (e) instructing the drive device to read the metadata from the position of the write-once disc, to obtain the metadata, and (f) the data is determined in step (d). Obtaining a next recordable address indicating a next recorded position in a track other than a track, wherein the track is selected from a plurality of tracks, (g) to reflect the recording of data specified by the recording request Updating the metadata, (h) instructing the drive device to write data specified by the write request at a location indicated by a recordable address in a write-once disc, and (i) the In the drive device, the updated meta data on the write-once disc to the position where the metadata is read in step (e). And perform a process comprising instructing to write at least some of the data.

In one embodiment of the invention, the controller comprises a semiconductor integrated circuit.

According to another feature of the invention, a program for use in a system controller for instructing a drive device having a pseudo-overwrite function to write data to a write-once disc including a plurality of tracks, the program Is the following steps: (a) receiving a write request specifying at least data for a file to be written, (b) instructing the drive device to read a file entry of a metadata file to Managing a file from a location of said write-once disc, (c) acquiring track information indicative of a location of each of said plurality of tracks; d) based on the file entry and track information of the metadata, from the plurality of tracks in which metadata is next recorded; Determining my tracks, (e) instructing the drive device to read the metadata from the location of the write-once disc, to obtain the metadata, and (f) the data is stored in step (d) Obtaining a next recordable address indicating a next recorded position in a track other than the determined track, wherein the track is selected from a plurality of tracks, (g) reflecting the recording of data specified by the recording request Updating the metadata in order to (h) instruct the drive to record the data specified by the write request at a location indicated by a recordable address in the write-once disc, and (i) The drive unit updates the metadata to the position where the metadata is read in step (e) on the write-once disc. Which it is a program configured to perform a process including the step of a command to record at least a portion of metadata.

According to another feature of the invention, a recording method for recording data on a write once disc, wherein the write once disc has a plurality of physical sectors, wherein the write once disc has a plurality of logical A volume space having sectors, each of the plurality of logical sectors corresponding to one of the plurality of physical sectors, wherein the write-once disc has a plurality of tracks, each of the plurality of tracks A recording method comprising at least one physical sector of the plurality of physical sectors, the method comprising: (a) receiving a write command specifying at least one logical sector on which data is to be recorded, (b) each of the plurality of tracks Obtaining track information indicating a position, (c) based on the logical sector designated by the recording command and the track information obtained in step (b), Determining one track from the plurality of tracks on which data is to be recorded; (d) determining whether a logical sector designated by the write command corresponds to a recorded physical sector or an unrecorded physical sector, (e) Recording data into the unrecorded physical sector when it is determined that the logical sector designated by the command corresponds to an unrecorded physical sector, (f) the logical sector designated by the write command is not recorded. When determined to correspond to a physical sector, data is written into the physical sector indicated by the next recordable address in the track determined in step (c), and the remapping address of the physical sector indicated by the next recordable address To remap the original address of the physical sector written to Generating a remapping table containing the remapping information.

In one embodiment of the invention, the method further comprises receiving an allocation command and allocating at least one track in response to the allocation command.

In one embodiment of the invention, the step of assigning at least one track comprises assigning a first track and a second track in the track determined in step (c).

According to still another aspect of the present invention, there is provided a driving apparatus for recording data on a write once disc, wherein the write once disc has a plurality of physical sectors, wherein the write once disc has a plurality of logical sectors. And a volume space having a plurality of logical sectors, each of the plurality of logical sectors corresponding to one of the plurality of physical sectors, wherein the write-once disc has a plurality of tracks, each of the plurality of tracks A drive apparatus comprising at least one physical sector of a plurality of physical sectors, comprising: a drive mechanism for performing a write operation to the write-once-type disc, and a drive control section for controlling the drive mechanism; Where the drive control section is the next step, namely (a) writing to specify at least one logical sector on which data is to be written. Receiving a command, (b) obtaining track information indicative of the position of each of the plurality of tracks, (c) based on the logical sector designated by the recording command and the track information obtained in step (b) Determining one track from the plurality of tracks on which data is recorded, (d) determining whether a logical sector designated by the write command corresponds to a recorded physical sector or an unrecorded physical sector, ( e) controlling the drive mechanism to write data to the unrecorded physical sector when it is determined that the logical sector designated by the command corresponds to an unrecorded physical sector, (f) in the write command The track determined in step (c), when it is determined by the logical sector designated by the Control the drive mechanism to write the data to the physical sector indicated by the next writable address in the apparatus, and write the original address of the physical sector recorded as the remapping address of the physical sector indicated by the next writable address. Generating a remapping table comprising remapping information for remapping, and controlling the drive mechanism to write the remapping table on the write-once disc.

According to another feature of the invention, a semiconductor integrated circuit for use in a drive device for recording data on a write-once disc, wherein the write once disc has a plurality of physical sectors, the write once write disc; The disc includes a volume space having a plurality of logical sectors, each of the plurality of logical sectors corresponding to one of the plurality of physical sectors, wherein the write-once disc has a plurality of tracks, and Each of the plurality of tracks includes at least one physical sector of the plurality of physical sectors, wherein the semiconductor integrated circuit is configured to control a driving mechanism for performing a write operation for a write-once disc. The semiconductor integrated circuit comprises the following steps: (a) at least one logical sector in which data is to be written. Receiving a recording command designating a recording command, (b) acquiring track information indicating the position of each of the plurality of tracks, (c) the logical command specified by the recording command and the track information obtained in step (b) Based on a sector, determining one track from the plurality of tracks on which data is recorded, (d) determining whether a logical sector specified by the write command corresponds to a recorded physical sector or an unrecorded physical sector; (E) controlling the drive mechanism to write data to the unrecorded physical sector when it is determined that the logical sector designated by the command corresponds to an unrecorded physical sector, (f) When it is determined that the logical sector designated by the write command corresponds to a physical sector that is not recorded, step (c) Control the drive mechanism to write the data to the physical sector indicated by the next writable address in the track determined at < RTI ID = 0.0 > and < / RTI > Generate a remapping table that includes remapping information for remapping the original address, and perform a process comprising controlling the drive mechanism to write the remapping table on the write-once disc. .

The above and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying drawings.

1 is a diagram showing the configuration of an area when a file is recorded.

FIG. 2 is a diagram showing the configuration of an area when a Data-A file is recorded in the root directory of a disc having a state as shown in FIG.

FIG. 3 is a diagram showing the structure of the area when the Data-A file is recorded in the root directory on the disc having a larger free area.

4 is a flowchart showing a procedure for recording a file.

5 is a diagram showing an optical disc information recording / reproducing system.

6 is a diagram illustrating command transfer between a drive device and a system controller.

7A to 7D each include a diagram showing a block in the user data area when data is remapped for a rewritable disc case and a once-writable disc case.

8A and 8B include diagrams showing blocks in a user data area, respectively, when data is recorded in the NWA.

9 is a diagram illustrating a data structure of a remapping table.

Each of FIGS. 10A-10E includes a diagram showing a configuration of an area for explaining a strategy of multi-track recording.

11 is a diagram showing the configuration of an area for explaining the pseudo-overwrite method.

12 is a diagram illustrating a configuration of an area having a track for recording metadata in a metadata mirror file.

Fig. 13 is a diagram showing the configuration of the area after a new track for metadata recording is assigned.

Fig. 14 is a diagram showing the structure of the area after metadata is recorded in a new track for metadata recording.

Each of FIGS. 15A-15D includes a diagram showing a block in a user data area when data is written using a pseudo-overwrite method.

FIG. 16 is a flowchart showing a process for recording data by a system performed in a controller of an optical disc information recording / reproducing system.

17A and 17B each include a flowchart showing a process for recording data by the driving apparatus of the optical disc information recording / reproducing system.

18 is a diagram illustrating an optical disc information recording / reproducing system that is part of a consumer video recorder or consumer video player.

FIG. 19 is a flowchart showing a process for recording data on a write-once optical disc by the recording / reproducing system described in FIG.

FIG. 20 is a flowchart showing a process for reading data from a write-once optical disc by the recording / reproducing system described in FIGS. 5 and 18. FIG.

Each of FIGS. 21A-21C includes an example of a track layout after logical format and after some files have been recorded.

The overwrite function for the write-once disc performed by the drive device has been studied. In practice, however, it was difficult because the drive did not know how much data was overwritten and where the data was overwritten.

For example, the data to be overwritten is stored in another location as a once-writable disc, and information for designating the original position and the replacement position must be processed in the drive unit. When the amount of overwrite data increases, it takes longer to find where it is replaced. Therefore, such a drive device cannot be read / written with sufficient performance because of low resources (eg, CPU speed and memory).

It will be appreciated that the new file system must distinguish between the data to be overwritten and the data to be newly written, and the new file system can be matched with a drive having an overwriteable function. And there is a possibility of applying a metadata partition for data attachment purpose on a write once disc without using VAT.

The strategic importance of this idea includes that the device adjusts the overwriting of existing blocks so that the file system does not need to perform logic. This makes the file system driver less complicated.

On the other hand, write-once media are one of the cheapest and fastest methods for recording data to erasable media. However, this essentially requires the drive to write data to a location on the disk. This position moves forward, as when data is recorded. Typically, this can substantially result in data destruction. That is, a given kind of data or file can be distributed over many locations on disk.

The idea described below is a method of alleviating some of the above-described breakdowns by using multiple recording points on a disc. In other words, metadata and files may be stored in separate locations on disk. By providing a mechanism for recording at different locations on the disc, some limitations on its usefulness can be removed.

In the following embodiments, a discussion based on the present idea is illustrated in detail.

(Example 1)

The amount of overwritten data can be reduced by optimizing the process in the system. In this embodiment, the basic read / write operation is described according to a new recording method for the drive apparatus with the overwriteable function of the write-once type disc.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 and 2 are diagrams showing the configuration of regions. 4 is a flowchart showing a process for recording a file. 1 shows a state after a logical format operation. FIG. 2 shows a state in which the Data-A file is recorded in the root directory on the disc having the state of FIG.

First, FIG. 1 is described.

The data area includes areas such as lead-in area, volume space and lead-out area (where the lead-in area and lead-out area are managed by the physical layer). Physical sectors are addressable units in the data area, and physical sector numbers are assigned to each physical sector in an ascending sequence. Volume space is made up of logical sectors, and logical sector numbers are allocated in ascending sequence for each logical sector. Each logical sector uniquely corresponds to a physical sector in advance. For example, a logical sector with logical sector number 0 corresponds to a physical sector with physical sector number 10000 and the start address of the volume space is stored in the lead-in area.

The defect management area (DMA) is an area in which information indicating the correspondence between the address of the block to be replaced and the address of the block to be replaced in the replacement operation is recorded as a defect list.

Temporal DMA (TDMA) is an area where a temporal defect list is recorded in an incremental write operation. When the disc is finalized to inhibit incremental write operations, the temporal defect list is registered as a defect list in the DMA. DMA is provided in two disk parts, internal and external. Thus, the defect list is recorded twice in two different areas. In the DMA, disc information such as track information, position information of the spare area, and the like is recorded.

The spare area is a replacement area in which data is recorded by a replacement operation, which corresponds to a linear replacement method. The spare area is allocated outside of the volume space handled by the file system. In this example, data was recorded in part of the spare area. Addresses in the spare area are essentially specified by using physical addresses. For the sake of simplicity, the relative address in the spare area is represented by SA (Spare area Address). Sectors in the spare area are left unrecorded.

In the present invention, the linear replacement algorithm generally used for defect management is applied to the overwriting performed by the drive device.

The volume space includes four tracks. One track is an area where data is recorded sequentially from the start of the track on the write-once disc. The end of the recorded area in the track is managed by the drive device. Track status (closed and open) indicates the status of the track. "Closed" indicates that all sectors in the track have been used for data recording. "Open" indicates that there is at least one sector not used for data recording. In other words, data can be incrementally recorded in the open track.

(Volume structure)

Volume and file structures are in accordance with UDF 2.5. A volume structure located in an area with a smaller logical sector number includes an anchor volume descriptor pointer, a volume recognition sequence, a volume descriptor sequence, and a logical volume integrity sequence. A volume structure located in an area with a larger logical sector number includes an anchor volume descriptor pointer and a volume descriptor sequence. The logical volume integrity sequence in which the logical volume integrity descriptor is written is part of the volume structure. Since the volume structure was previously recorded, tracks # 1 and # 4 are in a closed state. Track # 2 is an area designated for recording metadata. In Fig. 1, as an example, the metadata file assigned to track # 2 has an unrecorded area. Metadata files are also called metadata partitions. The area consisting of tracks # 2 and # 3 is called a physical partition. Track # 3 is an area designated to record data of a file. Therefore, the area following the recorded area is in an unrecorded state.

(File structure)

The metadata bitmap FE (metadata bitmap file file entry) is a file entry for organizing the area allocated for the metadata bitmap. The metadata bitmap is a bitmap for specifying the usable sectors prepared for use in the metadata file. Not only the unrecorded area but also the unused area by detecting a file entry or directory is also registered in the bitmap as an available area. The metadata file FE (file entry of the metadata file) is a file entry for organizing the area allocated for the metadata file. In the metadata file, file entries and directories are recorded. In a UDF, a file set descriptor is also written, which is not shown in the figure.

The root directory FE (root directory file entry) is a file entry for organizing the area allocated for the root directory. The root directory FE is recorded in MA # 0. The root directory is recorded in MA # 1. The MA (metadata file address) points to the relative address in the metadata file.

(File recording process)

An exemplary process for writing Data-A to the write-once disc of FIG. 1 is described with reference to FIGS. 2 and 4.

In step S101, the metadata bitmap is read into the memory and updated in the memory to obtain a recording area in the metadata file.

In step S102, the directory in which the file is registered is read into the memory and updated in the memory. In this example, the root directory is read and data-A is stored.

In step S103, the file entry of the directory is read into the memory and the information of the directory (e.g., size and update time, etc.) is updated.

In step S104, data-A is recorded from the beginning of the unrecorded area in track # 3.

In step S105, in order to register the positional information of the recorded data, an entry of the data-A file is generated in the memory.

In step S106, the metadata and the metadata bitmap updated or generated in the memory are recorded. In the root directory, the drive device receives a command and data is written to MA # 2 (unrecorded sector). Therefore, the root directory recorded in MA # 1 becomes invalid, and the sector of MA # 1 becomes a sector usable in the logical space. Although the drive device is commanded and data is recorded as the same as the usable area in the metadata file, the data cannot be physically recorded into the area as long as the area is already recorded. For file entries in the root directory, data is ordered to be written to MA # 0 (already written area), which data is stored as SA # 0 in the spare area, which is the beginning of the unrecorded area in the spare area. For an entry in the data-A file, the data is instructed to be written to MA # 3 (unrecorded sector). For a metadata bitmap, the data is instructed to be recorded at the same location (already recorded area), and then the data is stored as SA # 1.

The replace operation is the pseudo-overwrite operation of the present invention. As used herein, the term " pseudo overwrite operation " refers to a logical overwrite operation in which the data of the replacement operation is not recorded in response to a command for writing the data to an already recorded area. It is used to record.

In step S107, it is instructed that the logical volume integrity descriptor is updated to indicate the integrity status of the file command. The data is stored in the spare area by a pseudo overwrite operation (not shown in the figure).

As described in step S106, as many pieces of data as possible are recorded in the same ECC block by using a cache by recording a plurality of pieces of data together, it is possible to effectively utilize the unrecorded area. In particular, the metadata bitmap or logical volume integrity descriptor may not be updated each time a file is written. By recording the metadata bitmap or logical volume integrity descriptor after a plurality of files have been recorded, it is possible to effectively use the unrecorded area of the spare area.

The Data-A file is read in the following manner. The volume structure in track # 1 is read. Then, to access the metadata file, the file entry of the metadata is read. Then, when the file entry of the root directory is read, the area outside of the optical disc needs to be accessed because the actual data is recorded in the spare area. Thereafter, the file entry of the root directory recorded in sector MA # 2 and the data-A file recorded in sector MA # 3 is read. Thus, file data can be accessed as address information of Data-A is obtained.

5 shows an optical disc information recording / reproducing system 500 according to the present invention. This information recording / reproducing system 500 includes a system controller 510, a drive device 520 for reading and recording information from an optical disc, and an input / output bus 530.

Between the system controller 510 and the drive device 520, the transfer of commands and responses and read / write data using the command set is performed via the input / output bus 530.

System controller 510 includes a controller 511 and a memory 512. System controller 510 may be a personal computer. The controller 511 may be, for example, a semiconductor integrated circuit such as a CPU (Central Processing Unit) and is described in the embodiments of the present invention to perform the method.

Also stored in memory 512 is a program for causing controller 511 to perform the method described in these embodiments. In the controller 511, a file system, a utility program or a device driver may be performed.

Drive device 520 includes a system LSI 512, a memory 522, and a drive mechanism 523. A program may be stored in the memory 522 that causes the system LSI 521 to perform the method described in embodiments of the present invention. System LSI 512 may be formed on a semiconductor chip and may include a macro processor.

The drive mechanism 523 includes a mechanism for loading an optical disc, a pickup 524 for recording / reading data to or from the disc, and a traverse mechanism for moving the pickup 524.

As mentioned above, the data in the file can be written without being overwritten, and some metadata can be written using pseudo-overwrite. Typically, the size of the metadata needed to update the file is smaller than the data size of the file, and the size of the overwritten data can then be reduced. The size of the file entry is 2048 bytes, and the size of the directory depends on the number of files and the length of the file name. For example, if each file name is 12 characters and 39 files are recorded in the directory, the directory information may be recorded in a 2048 byte sector. Therefore, the read / write operation can be basically realized for the write-once type disc by combining the new recording method and the driving device with the overwritten function.

(Example 2)

This embodiment describes a recording method for improving access performance when one file is read by pre-recording all areas in the metadata file.

In UDF 2.5, metadata files were introduced to record metadata, such as file entries and directory information in localized areas, in order to ensure that metadata is not distributed within volume space, providing efficient access to management information. do. It also significantly improves performance when metadata on a damaged disk is repaired by a utility such as a scan disk. However, as described in Embodiment 1, some data in the metadata file is inevitably written to the spare area when the data needs to be subject to a pseudo-overwrite operation. Therefore, separate access time is required. If the number of files to be recorded is small, separate access time is not a serious problem. However, as the hierarchy of directories gets deeper and the number of files under each directory increases, the time required to access a designated file becomes complicated, especially for large optical discs.

In this embodiment, all areas in the metadata file are recorded at the time of logical format. FIG. 3 is a diagram illustrating a configuration of an area on a disc on which data as shown in FIG. 2 is recorded. The difference between FIG. 3 and FIG. 2 is that the area allocated for the metadata file is recorded before the file is recorded. Therefore, track # 2 is in a closed state.

The procedure for recording the data-A file is described below with reference to FIG. The file system commands the drive to write the root directory logically to MA # 2. Although the data is recorded as a logically available area in the metadata file, the area in the metadata file is an already recorded area. Therefore, the root directory is physically written to SA # 0 by a pseudo-overwrite operation. Similarly, data is physically written to SA # 1 by a pseudo-overwrite operation, even though the file system commands to log the root directory FE logically to MA # 0. Then, the data of the data-A file is recorded in the track # 3 from the start of the unrecorded area. The file system acquires the address information of the beginning of the unrecorded area before performing the write operation. To specify the location where the Data-A file is written, the file system instructs the file entries of the Data-A file to be logically written to MA # 3 and the data is actually written to SA # 2 by a pseudo-overwrite operation. .

The file system recognizes that the root directory, root directory FE, and data-A FE are logically recorded in the metadata file. As the pseudo-overwrite operation is performed by the optical disk drive, only logical address information is passed through the interface between the drive and the system controller. At this time, MA # 1 is available, and MA # 2 and MA # 3 are logically recorded areas in the metadata file. This file system instructs the metadata bitmap to be updated and written to indicate the above state, and then the corresponding data is written to SA # 3 in the redundant area by a pseudo-overwrite operation.

The data-A file of Fig. 3, recorded by the recording method of the present invention, is read as follows. After reading the volume structure from track # 1, the file entry of the metadata file is read. Thereafter, the file entry of the root directory, the root directory, and the file entry of data-A in the spare area are read. All of this information was recorded in the extra area by a pseudo-overwrite operation. Therefore, no access is required between the metadata file and the extra area.

A unique purpose of introducing metadata files is achieved. This is because even though the metadata file is logically allocated in the physical partition, the data written to the metadata file is actually written to the spare area by a pseudo-overwrite operation. Thus, data is recorded in the extra area regardless of whether or not there is a defect in the metadata file.

6 is a diagram illustrating data transfer with commands between a drive and a system controller. Certain orders may apply to standards set by the ANSI (American National Standards Organization) or multi-media committee set standards defined by INCITS (International Commission for Information Technology Standards) T10.

Steps S601, S603, S605, and S607 indicate the process performed by the system controller. Steps S602, S604, S606, and S608 indicate the process of the driving device.

In step S6012, the type of medium loaded in the driving device is requested from the system controller, and the system controller recognizes that the medium is a write-once pseudo-overwriteable disk and recognizes that the driving device supports the pseudo-overwrite function.

In step S602, the driving apparatus reads out information on the type of the loaded disc. The drive also determines whether the pseudo-overwrite function is supported for the disk. The drive informs the system controller of this piece of information.

In step S603, by requesting the track information of the write-once type disc, the system controller obtains the information from the drive device. In particular, the size of the unrecorded area of track # 3, and the last recordable address in the track or the last unrecorded address in the track are requested. In order to record the data of the file, it is necessary to take the above-described information in advance, and it is checked whether the unrecorded area is at or above the designated size. For example, since additional metadata files may be allocated in track # 3, the specified size may be 128 MB for a disk whose total volume is 23 GB. If the size of the unrecorded area is smaller than the specified size, the disc is used as a read only disc. If the size is equal to or larger than the specified size, the process goes to the next step. The file entry is 2KB in size. When only a file entry is recorded in the available area 128MB, a file entry corresponding to at most 65,536 files can be recorded.

In step S604, the driving apparatus reads out the number of tracks, the positional information or the open / closed state of each track, or information related to the last recorded address information from the lead-in area of the loaded disc, DMA, or TDMA. . This piece of information is known to the system controller.

In step S605, a command is transmitted to the drive device to read the metadata bitmap area. As a result, the system controller obtains the metadata bitmap and checks whether there are available sectors. If there are available sectors, the process goes to the next step. If no sector is available, an additional area for the metadata file is designated in the unrecorded area of track # 3 to store the available sector. In this check, the system controller may use the specified size for the available sectors to determine whether additional areas for the metadata file are stored, which may be for example 128 KB.

In step S606, the driving device reads data from the designated area and transfers the data to the system controller.

In step S607, by requesting the spare device for spare area information, the system controller acquires the information and checks whether there is an unrecorded area in the spare area having a specified or larger size.

For example, when the size of the unrecorded area is equal to or larger than 8 MB, the disc cannot be used as a recordable disc. When the size is smaller than 8MB, the disk is used as a read only disk. The redundant area is used for defect management as well as pseudo-overwrite. Therefore, additionally unrecorded areas need to recover defective sectors on the disc.

In step S608, the drive apparatus reads out the number of spare areas, the size of the spare areas, and the size of the unrecorded areas in each spare area from the lead-in area, DMA or TDMA of the loaded disc. This piece of information is known to the system controller.

As described above, data is recorded in an unrecorded area in the redundant area by pseudo-overwrite or defect management. The write-once disc drive device of the present invention has a function for transmitting not only the type information of the medium but also the free area information to the system controller, where the drive device has data at a position that may be different from the location expected by the file system. Because it saves. By requesting this free area information each time a file is written, the system controller determines whether the file can be written and, as a result, the system controller can accurately record the file with the relevant data in the metadata file.

(Example 3)

In the previous embodiment 2, the metadata is remapped to extra areas to reduce the access time for retrieving the metadata. For this purpose, since the size of the space cannot be expanded afterwards, an extra area with sufficient size must be specified at the formatting time on the write-once disc. However, the user cannot know the number of files and the size of the files to be recorded on the disk, and therefore, it is difficult to determine the proper size of the spare area at the formatting time. If all spare areas are used, even if an unrecorded area remains in the user data area, the file cannot be recorded on the disc. On the other hand, if a larger spare area is specified, after all the user data areas are used, unused areas may remain in the spare area.

Moreover, in the example of Embodiment 2, more entries may be used in the remapping table than Embodiment 1. This requires a drive that can process more tables to retrieve the remapped sectors. The file system driver must check the size of the unrecorded area in the spare area every time a file is written, thus making space management difficult.

Therefore, the following describes a recording method in which an instruction for replacing data in the user data area as well as in the spare area is described.

First, the idea of the present invention is explained.

The devices handle the overwriting of existing data by writing new data to the next recordable block and creating an entry to remap the table stored by the drive. The file system continues to use the same logical block number, and the drive remaps the request to a new location based on the entry in the table. To reduce the size of this table, the file system does not reuse blocks after it is freed. In other words, the file system must be aware that it is using a write-once medium, and therefore must adjust its behavior.

The device uses normal volume space to store the remapped data. That is, it records at the next recordable position in the same track as the original block exists. The file system queries the device for the next recordable block whenever it needs to allocate new space. Thus, the file system and the device share the same space for recording.

Secondly, the effects of the above-described idea are explained using Figs. 7A-7D, 8A-8B and 9.

7A-7D and 8A-8B show blocks in the user data area. In the present application, blocks are generally used rather than sectors to illustrate the idea. The user data area is recognized as a volume space by the file system. For each block, a physical block address (hereinafter referred to as PBA) and a logical block address (hereinafter referred to as LBA) are specified so that the correspondence between PBA and LBA is predetermined, as an example PBA from number 100. LBA is specified from number 0.

9 shows the data structure of the remapping table stored by the drive device. The table has entries, each entry specifying an original address and a remapping address. This data structure can be a common data structure having a defect list used for defect management for a recordable disc.

Typically, the ideas described above were considered ineffective because they were contradictory when applied to recordable discs.

As shown in Fig. 7A, the recordable disc has a spare area, where the PBA is designated from the number 200, for example. In the general case for a recordable disc, if data is written to blocks of LBA 2 and 5 and these blocks are defective, this data is stored into blocks PBA 200 and 201 in the redundant area using a linear replacement algorithm. This means that LBA 2 and 5 are reassigned to PBA 200 and 201. Thus, when some blocks in the volume space become unusable blocks due to defects, they are compensated for by good blocks in the spare area.

If the above-described idea has been applied to a recordable disc, as shown in Fig. 7B, data for recording LBAs 2 and 5 are stored in blocks in the user data area, for example, PBAs 103 and 107. However, these remapped blocks, PBA 103 and 107, cannot be used to store the data requested in LBA 3 and 7, since these blocks are replaced as LBA 2 and 5. This situation violates the assumption that it provides a logical space free of defects and refers to the assumption that when any data is written by the file system, the data volume on the recordable disc is not reduced. Moreover, in this situation, the drive cannot determine a location for remapping the data, because the file system can randomly record the data and only the file system can create a spatial bitmap that specifies the available area for recording. Because it is controlled.

As described in Example 1, the linear replacement algorithm can also be applied to the write-once disc. As shown in Fig. 7C, the spare area is assigned to the one-time recording disc in advance. If a block cannot be overwritten or written due to a defect, the block is compensated for by a block in the spare area. For example, when data D1 is written to LBA 2, if the block is defective, this block is compensated with a PBA 200 block. When LBA 5 is written by data D2, data is stored in PBA 201 even though PBA 105 has already been recorded.

Suppose that an overwritten and defective block is compensated for by another block that falls outside of the volume space. This idea is likely to be contradictory not only for rewritable discs, but also for single-writable discs.

However, according to the present invention, a write once disc does not guarantee to provide a defect free logical space, such as a rewritable disc, because once a block on a write once disc has been written, it is possible to change the data in the block. Because it is impossible. And new file systems for write-once discs record data using sequential writes. In this respect, this idea is effective for the write-once disc as shown in Fig. 7D. Data D1, D2, and D3 are sequentially recorded as LBAs 0, 1, and 2, and if block PBA 102 is defective, data can be written to the next block PBA 103. Furthermore, data D4, D5 and D6 are written sequentially to LBA 4, 5 and 6, and then updated data D5 'can be overwritten to LBA 5. In this overwriting, data is stored in block PBA 107 which is the next recordable position. Thus, this idea does not require changing the designation of logical block numbers, because each time an overwrite is required, it can be written to the next recordable position until the user data area is exhausted. In the case of a rewritable disc, data cannot be written to the block used for remapping, but there is no problem with the write-once disc of the present invention. For example, data is stored in PBA 108 and an entry for specifying such remapping from the original address of PBA 107 to the remapping address of PBA 108 is added to the remapping table.

As described above, according to the present invention, even if the logical block address is double blocking, the driving device can write data by designating a new physical block address as NWA.

Another practical point about the above-mentioned idea is to get the entries stored in the remapping table by querying the next writable address from the file system to the drive. 8A and 8B illustrate a mechanism for reducing the size of the table. In this figure, blocks PBA 100 to 105 are previously recorded. As shown in Fig. 8A, when data D1 is written to LBA 1, the data is stored in the next recordable position PBA 106 and one entry added to designate PBA 101 is remapped to PBA 106. At this point, the file system does not know where the data is being remapped. If the file system instructs the new data D2 to be written to the previous next recordable position LBA 6, the data is stored in the next block PBA 107 and one entry is added. In the present invention, the file system checks the next writable address updated before any data is written except for overwriting, and instructs the data to be written to the next writable address LBA 7 of FIG. 8B. . Thus, no additional entry is needed. The file system also does not allocate data to the erased file area, except for the requirement to be overwritten for the same reason.

Moreover, space management by the file system is simplified because the file system only uses the NWA in each track to allocate a new area for recording. This means that the file system may not be checked in the spare area and may not record spatial bitmaps, especially metadata bitmaps.

The unit for remapping the region may be an ECC block including a plurality of physical sectors. When a physical sector is remapped, all physical sectors in the ECC block to which the physical sector belongs are remapped. In this case, the original address and the remapping address in the entry of the remapping table are specified by the physical address of the starting sector of the ECC block. As addressable units, physical blocks and logical blocks can be physical sectors and logical sectors. Even if one sector is newly recorded, one ECC block including the sector is written, and then the NWA is moved to the starting sector of the next ECC block. Therefore, when several data are recorded, such data is allocated so that such data is recorded in the same ECC block.

With the present invention, the advantage of using metadata partitions can be provided for use on write-once discs. First, the data to be overwritten is remapped in the track for metadata recording, then access to retrieve metadata is localized and search performance is improved. Normally, overwritten data is stored in the same track as long as the track has unsectored sectors. When a track is depleted by data recording, the overwritten data can be stored in another track, since priority is given to writing the data to other unrecorded physical blocks within the same track. Secondly, the metadata file can be recorded to improve durability, which can be recorded when additional tracks for the metadata mirror file are specified.

These advantages come from the following idea. That is, when recording data, the file system determines which track to use based on the type of data. It then queries the device to determine the location of the next recording point for this track. When a track is full, the file system can arbitrarily determine different tracks.

As an example, consider a piece of media that is formatted as two tracks. The first track is used to store metadata. The second track is used to store file data. When the file system needs to record the metadata, it queries the device for the recording point of the first track and uses that location for storing the metadata. If the file system needs to record file data, it queries the device for the recording point of the second track and uses that location for storing the file data. Whichever track becomes full, the file system can decide to use free space that can exist within other tracks. This allows the file system to group metadata together and to group as much file data together as possible. By grouping the data together, fragmentation is reduced.

This idea can be used by the Universal Disc Format (UDF) file system. Some of the advantages of version 2.50 can be used on write-once media. At the present time, UDF 2.50 requires rewritable media due to the way metadata is stored. One of the main reasons why UDF 2.50 was developed was to group metadata together, apart from file data. This advantage is lost in write-once media. By using this idea, this advantage can be realized on a write-once medium.

This idea may be used to group similar data together for a specific purpose. For example, audio may be stored on one track and video may be stored on another track. Alternatively, the still picture may be stored in one track and the video may be stored in another track. The advantage here is to separate the data with different update patterns. If a user frequently creates, edits, and erases an image, this data can remain separated from the video that is added continuously. This prevents picture data from intermixing with the video stream.

If two tracks are reserved, a special allocation method can be used. This method creates a reserved track of one fixed size and leaves the second track open. When the first track becomes full, the second track is closed at the current recording point and two new tracks are created. This new track follows the same pattern as the first two tracks. This can continue until the disk is full. This allows file systems to be grouped together into the same data in large chunks. For example, this allows the metadata to be stored in large chunks on a write-once medium in a manner similar to the way that metadata is stored in UDF 2.50 on a recordable medium.

10A-10E are diagrams illustrating a configuration of an area for explaining the multi-track recording strategy described above. A special allocation method is shown in FIGS. 10A-10E.

In Fig. 10A, two tracks are reserved for recording metadata and file data. When the first track for metadata is exhausted, the file system requests the drive to specify a new track in the track for data as shown in FIG. 10B. New track # 3 for metadata recording is then reserved in track # 2 in FIG. 10A, and the remaining track # 4 can be used for data recording. It is evident that there are no longer any NWAs in tracks # 1 and # 2. As tracks # 3 and # 4 are newly assigned, the NWA is available at the starting address in the newly designated track. In FIG. 10C, metadata and file data can be recorded as new tracks, tracks # 3 and # 4.

In Fig. 10D, two tracks are reserved for recording metadata and file data. In this case, track # 1 for metadata recording is larger than the track described in Fig. 10A to record metadata as needed. When the second track for data is depleted, as shown in FIG. 10E, the file system requests the drive to designate a new track behind the track for metadata so that the first track and the second track can be deleted. Has an unrecorded area. A new track # 2 for data recording is then reserved for track # 1 in FIG. 10D, so that a shorter track is assigned as track # 1. After the track # 2 is reserved, the number of tracks of the track # 2 in FIG. 10D is changed to the track # 3 in FIG. 10E. NWA no longer exists in track # 3. Since track # 2 is newly assigned, the NWA can be used at the starting address in the newly reserved track. In Fig. 10E, metadata and file data can be recorded as new tracks, tracks # 1 and # 2.

Here, the potential for overwriting is estimated for the illustrated case where the volume of the disk is 23 GB (= 23 x 1024 ^ 3 bytes), the ECC block consists of 32 sectors, and the sector size is 2 KB (= 2 x1024 bytes). )to be. If the average size of the file recorded on the disk is 128 KB and 10 files are stored in the directory on average, about 188,000 files and 18,800 directories can be recorded on the disk. When the file system densifies file entries to be updated with ECC blocks, about 6,400 entries are required for the remapping table. The size of the table is about 50KB when the entry size is 8 bytes. When the drive can handle 256 KB of the remapping table as the maximum size, 188,000 files and 18,800 directories can be recorded at random. Therefore, the present invention is applied to the next generation write-once optical disc using blue laser technology.

Examples of applying the above ideas to UDF-based new file systems and next-generation write-once discs are described.

11 is a diagram illustrating a configuration of an area for explaining the above-described remapping. The area layout described in Embodiment 1 is also used in this embodiment.

The defect management area (DMA) is an area in which a defect list is recorded and where temporal DMA (TDMA) is one area, where a temporal defect list is recorded. The remapping table can be written to DMA and TDMA with a defect list and a temporal defect list. Here, the defect list and the temporal defect list can be used to specify replacement information by defect management and remapping information using the same data structure. This simplifies the implementation of the drive because the interpretation of entries is common for defect management and pseudo-overwrite. When an entry specifies remapping information, the entry in the table indicates the correspondence between the address of the block to be remapped and the address of the remapped block.

The spare area is designated from the volume space, and the address in the spare area is indicated by SA (extra area address).

The volume space includes three tracks, each of which records data sequentially. The start address of the unrecorded area in the track is managed as the next recordable address (NWA). The state of a track is described in new terms, "used" and "prepared" to indicate the data in these tracks means that the data in these tracks can be overwritten and the data can be remapped within the reserved track. Appear. Used track means that all sectors in the track have been used for data recording. Spare track means that there are sectors that are not recorded. In other words, data can be incrementally recorded to the reserved track. Since the volume structure was previously recorded, track # 1 is the track used. Track # 2 is a spare track designated for metadata recording. Track # 3 is a spare track designated for recording user data.

An exemplary process for updating a Data-A file and writing a Data-B file to a write-once optical disc is described.

First, the metadata file FE is read to obtain the area allocated for the metadata file and track information is obtained. The file system can then recognize which track can be used for metadata recording, where the MA (metadata file address) indicates the relative address in the metadata file.

When the file system updates a Data-A file, the file entry is read from memory and the file entry contains information for specifying where the updated data is written and related information in the memory (e.g., size and updated time, Etc.) to register. The file system instructs the drive to logically overwrite the data in the Data-A file. The drive then physically stores the data (Data-A ') as an NWA as the corresponding physical sector has already been recorded and the drive adds an entry to the defect list. If the file system instructs the drive to write data to the NWA after querying the drive, it is not required to add an entry in the defect list. In the present invention, this manner of storing entries is not recommended because the location of the data can be registered within the file entry. However, when a portion of a large file needs to be updated, the data to be updated may be overwritten instead of recording the entire data of the file. After the data has been recorded on the disk, the file system instructs to logically overwrite the file entry (Data-A'FE) to specify the recorded data and the updated time. The drive device then physically writes data into the sector shown in MA # k + 1 and stores the entry as a defect list.

When the file system newly writes Data-B under the root directory, the directory is read into memory and the directory is updated to add new files (data-B files) to this directory in memory. Before the file entry of the Data-B file is created in memory, the data of the Data-B file is written to the NWA in track # 3, followed by the file entry (Data-B FE) and the root directory in memory in the MA in track # 2. It is recorded from the NWA shown as # k + 2. To specify the new location of the root directory, an updated file entry for the directory is ordered for overwriting and data is written to the NWA shown as MA # k + 4. Thus, file entries of directories between metadata are overwritten to store entries, and other metadata (file entries and directories of files) and data of files are written without overwriting.

In order to indicate the integrity of the file structure, the updated logical volume integrity descriptor is instructed to overwrite (not shown in this figure).

In the above pseudo-overwrite operation, the data to be overwritten can be stored in the spare area or the NWA of the reserved track in response to a command to write data into the already recorded area. The destination for storing data can be determined by the drive device. Similarly, when data cannot be written to a sector due to a defect, the data can be replaced in an NWA or an extra area in the track by defect management.

In the case of a rewritable disc, the file system reuses the available area. However, in the present invention the usable area is not reused once used. For example, in FIG. 11, even if the logical directory of the reused MA # i + 1 becomes a usable sector, the file system does not allocate any data in MA # i + 1. If the data has been written back to MA # i + 1, the data is remapped. In the case where data is recorded on the ECC block basis, only one sector of the ECC block is instructed to be recorded and one ECC block is recorded even though invalid data is recorded in another sector of the ECC block. The file system does not reuse an area where invalid data is recorded for the same reason.

12 is a diagram illustrating a configuration of an area for explaining the remapping described above. Similar to Fig. 11, the Data-A file is updated and the Data-B file is newly recorded. In comparison with FIG. 11, the track intended to be used for the metadata mirror file is additionally reserved as track # 4, and the metadata mirror file FE specifies the location of the metadata mirror file. According to UDF 2.5, any metadata is written to the same relative address in the metadata file and the metadata mirror file, if a metadata mirror file exists. Although the metadata mirror file FE is not shown in Figs. 11, 13 and 14 for simplicity, when the metadata mirror file does not exist, the metadata file FE indicates the location of the metadata file.

An example process of updating Data-A and recording a Data-B file to a write-once optical disc is the same as the description of FIG. In this example, after the metadata is written to the metadata file, the same metadata is written to the metadata mirror file. The file system instructs the drive to know the area allocated for the metadata file and the metadata mirror file to read the metadata file FE and the metadata mirror file FE. The file system then recognizes which tracks can be used for metadata recording, where the MA (metadata file address) indicates the relative addresses in the metadata file and the metadata mirror file.

If the file system updates the data-A file, after the file system instructs to logically overwrite the file entry (data-A'FE) in track # 2 for the metadata file, the file system tells the drive unit. Command to overwrite the same file entry with the same relative address MA #k in the metadata mirror file. This drive physically writes data into the sector shown in MA # k + 1 and stores the entry as a defect list.

When the file system writes data-B newly in the root directory, the file system writes the file entry (data-B FE) from the NWA and the root directory to the metadata file of track # 2 as shown as MA # k + 2. After instructing to write, the file system instructs the driving device to write the same file entry and the same root directory from NWA shown as MA # 2k + 2 to the metadata mirror file of track # 4. Then, after the file system instructs NWA shown as MA # k + 4 to overwrite the metadata file of track # 2 with the updated file entry for the directory, the file system reads NWA shown as MA # k + 4. Command to overwrite the same updated file entry in the metadata mirror file of track # 4.

Thus, as the same metadata is recorded at the same relative address in the metadata file and the metadata mirror file, the durability when the metadata is read is improved.

FIG. 13 is a diagram illustrating a configuration of an area for explaining the aforementioned remapping. In FIG. 13, the newly reserved track is designated as track # 3 on the volume space described in FIG. This track is reserved in an unrecorded area in the track for recording user data, since track # 2 for metadata is depleted. For example, track # 3 in FIG. 11 ends at the end of the recorded area, and new track # 4 is designated from the unrecorded area after the end of track # 3.

14 is a diagram illustrating a configuration of an area for explaining the remapping described above. In Fig. 14, the Data-C file is newly written to the root directory on the volume space described in Fig. 13. The directory is read into memory and the directory is updated to add new files (data-C files) to these directories in memory. The file entry of the Data-C file is created in memory, and the data of the Data-C file is written to the NWA in track # 5, followed by the file entry (Data-C FE) and the root directory on memory in MA # in track # 4. It is recorded from the NWA shown as k + 5. In order to specify the new location of the root directory, the file entry updated for the directory is commanded to be overwritten in MA # 1. As track # 2 runs out, data is recorded in the NWA in other tracks. In this example, data is recorded in MA # k + 7 in track # 4. The metadata file FE is commanded to overwrite to specify an additional degree # 2 of the metadata file, and the data is recorded in the NWA shown as MA # k + 8. The degree assigned for the metadata file may not be the same as the newly designated track, because the degree of the metadata file can be extended by updating the metadata file FE. Thus, the degree of metadata file can be part of the track.

The recording process of the present invention is described below. This recording process is performed by the optical disc information recording / reproducing system described in FIG.

15A-15D each include a diagram illustrating a block within a user data area when data is written using a pseudo-overwrite method. User data areas, PBAs and LBAs are defined as described in FIG.

The procedure for updating the file is described in Figures 15A and 15B. As shown in Fig. 15A, before the file is updated, blocks PBA 100, 101 and 102 are recorded, and two tracks are reserved. The file entry D3 of the file to be updated is stored in block LBA 2. As shown in Figure 15B, the file system is

1) command to read a file entry from LBA 2 in advance;

2) query the drive for NWA,

3) Command to write the updated data D4 of the file to the NWA (LBA 9) in the track for data recording so that the data is recorded without overwriting and creating the file entry D3 'to read the position information in the file entry Is changed to specify the area in which the updated data is recorded, and then

4) The file entry is overwritten by instructing the updated file entry D3 'to be written to LBA2 in the track for metadata recording. In this example, data D3 'is physically recorded in PBA 110, as when the previous recording was in PBA 109. Therefore, at the time of overwriting, the drive device may record data in another track.

The process of writing a file in a directory is described in Figures 15C and 15D. As shown in Fig. 15C, blocks PBA 100, 101, 102, 108, and 109 are recorded, and two tracks are reserved. The file entries D1 and directory D2 of the directory are stored in blocks LBA 0 and 1. As shown in Fig. 15D, the file system is

1) command to read the directory's file entries and directories from LBA 0,

2) command to read the directory from LBA 1,

3) query the drive for the NWA of each track to determine the location for recording data without overwriting;

3-1) creates a file entry D6 of the file having the location information of the area allocated for the data of the file,

3-2) A directory D7 is created so that a new file is registered in the reading directory D2.

3-3) a file entry D1 'of the directory is generated to change the location information in the read file entry D1 to designate an area to which the updated directory is assigned,

4) command to record the data (D5) of the file to NWA (LBA 10) in track # 2 for data recording,

5) command to record the file entry (D6) of the file from NWA (LBA 3) in track # 1 for metadata recording,

6) Data is continuously recorded by instructing the directory D7 to be written to the next address,

7) Command to write the updated file entry D1 'to LBA0 so that the file entry is overwritten.

Thus, before any data is written, the file system queries the NWA. This is because the NWA may change as the drive device records data by remapping itself. Next, the file system provides a command for recording data from the NWA so that the data is written without being overwritten. The file system then instructs the updated data to be overwritten. This sequence of recording data is important for saving entries in the remapping table.

In the case of Fig. 15B, if the writing process is not such a sequence, if so-called data D3 'is overwritten before data D4 is written, data D3' can be written to PBA 109 and the NWA is changed. This means that data D4 is overwritten with LBA 9, but the data is remapped to PBA 110. In the case of Fig. 15D, if the writing process is not such a sequence, an unsolicited entry may also be added to the remapping table.

In the case of a rewritable disc, there is no such requirement. Typically, different sequences are used for rewritable discs in order to improve reliability in consideration of recovery when the recording process ends in an accident. On the other hand, such recovery is not important in the case of a write once disc. Rather, it is important to save entries in the remapping table because the previous state is maintained by the one-time write feature.

11A and 11B each include a flow chart illustrating a process for recording data on a write-once optical disc. This recording process is performed by the optical disc information recording / reproducing system described in FIG.

When a file is updated, the file system instructs the data in the file to be written so that the data is written without overwriting, and the file system creates a file entry by updating the recorded file and instructs the file entry to be written so that the file entry is Overwritten.

When a new file is written under a directory, the file system creates a file entry of the file and creates a directory and file entry of the directory by updating the recorded directory and its file entry in memory and records the file's data, file entry and directory. Command to write such data without overwriting it. The file system then instructs the file entry of the directory to be written, thereby overwriting the file entry.

Figure 16 shows the steps involved in the process for recording data on a write-once optical disc. One program is used to perform this process and is executed by the controller 511 included in the system controller 510. The system controller 510 instructs the drive device 520 to record data on the write-once optical disc. The controller 511 may include a semiconductor integrated circuit. This program is provided in several ways. For example, the program may be provided in the form of a computer-readable medium in which the program is recorded. Instead, the program may be provided by downloading a program from a server via the Internet. When this program is installed in a computer, the computer functions as the system controller 510. The write-once optical disc includes a plurality of tracks.

17A and 17B illustrate a process performed by the driving device 520.

In step S1601, the system controller 510 receives a recording request specifying a file to be recorded from at least the user. For example, this request would replace the Data-A file with new data and copy the Data-B file from another medium under the root directory on this disk. The recorded data is transferred to the memory 512 of the system controller 510 and the destination for recording the data is indicated by the path name of the directory tree structure.

In step S1602, the controller 511 instructs the driving device 520 to record the file entry of metadata, that is, the metadata file FE, which manages the file requested by the user from the write-once disk. To include metadata. From this, metadata, file FE are obtained.

In step S1603, the controller 511 instructs the driving device 520 to acquire track information indicating the position of each of the plurality of tracks.

In step S1604, the controller 511 checks each track to determine the track to which metadata is next recorded based on the file entry of the metadata file and track information. If part of the track is specified for the size of the metadata file or metadata mirror file, the track is used to record the metadata into the metadata file or the metadata mirror file respectively.

 In step S1605, the controller 511 instructs the driving apparatus to read the metadata from the position of the write-once optical disc, thereby obtaining the metadata. Metadata such as file entries and directories are read from the metadata file.

In step S1606, before the controller 511 instructs the drive device 520 to record data, the drive device 520 for the next recordable address NWA indicating the next recordable position of the data in the track. Query). This is because the drive device 520 may move the NWA. The driving device 520 transmits the queried NWA to the controller 511, and the system controller 510 transmits the NWA to the controller 511. The track is selected from a plurality of tracks. The controller 511 may query NWAs for a plurality of tracks, but at least query NWAs for tracks other than the track determined in step S1604.

In step S1607, the controller 511 determines whether the next recordable address NWA in the track determined in step S1604 is valid. If the NWA in the track is valid, the process goes to step S1608. For example, if a valid address is returned as NWA in step S1606, it can be recognized that there is no NWA in the track. In step S1604 or S1606, the state of the track may be queried through the query to the drive device 520. If the track is used, there is no NWA on the track.

In step S1608, the controller 511 instructs the driving device 520 to allocate a first track in which metadata is next recorded and a second track in which data is next recorded. Since the file system instructs the driving device 520 to allocate a new track, the controller 511 can update the NWA obtained in step S1606 with the NWA in the second track. In the case of Fig. 13, the NWA is at least a state address in tracks # 4 and # 5. The first track and the second track are allocated in the track selected in step S1606.

In step S1609, in response to the user recording request, the controller 511 generates or updates at least a portion of the metadata to minimize the amount of data to be overwritten by distinguishing the type of data to be recorded. As described in the description of FIG. 11, when a file is updated, the file system creates a file entry to specify the location of the data to be recorded. These file entries are the data that will be overwritten. If a new file is written under the directory, the file system updates the directory to create a file entry of the new file and register the new file and file entry of the directory. File entries in a directory are data that will be overwritten and other metadata can be written without being overwritten. As an example of updated metadata, the updated metadata may include a file entry of a directory in which the file is recorded or a file entry of the file.

In step S1610, the controller 511 instructs the driving device 520 to record data that can be recorded without being overwritten at the position indicated by the NWA.

In step S1611, the controller 511 instructs the drive device 520 to write at least a part of the updated metadata at the location where the metadata is read, so that the data is overwritten in the logical sector. In steps S1610 and S1611, the same write command can be used as a command for recording data, since the driving device can determine whether the data should be written without overwriting or without checking the state of the logical sector in step S1702. to be. In steps S1610 and S1611, data is recorded at different addresses indicated in different ways, for example, step S1610 records data specified by a user write request (step S1601), and step S1611 writes the read metadata. Record (step S1602). Step S1611 is performed after step S1610 to avoid the possibility of an error.

In step S1612, the controller 511 determines whether the first track is assigned and whether at least a portion of the updated metadata is recorded in the first track. If it is determined that the first track has been allocated and at least a portion of the updated metadata has been recorded in the first track, the process proceeds to step S1613.

In step S1613, the controller 511 updates the file entry of metadata to reflect the recording of at least a portion of the updated metadata, and instructs the driving device 520 to read the file entry of the metadata file in step S1602. To record the updated file entry of the metadata file at the location.

In response to a command from the controller 511 for recording data, a process following the drive device 520 is shown in Fig. 17A.

In step S1701, the drive device 520 receives a write command from the controller 511 specifying at least a logical sector in which data is recorded and checks which track is recorded. The drive device 520 also obtains track information indicating the position of each of the plurality of tracks, and determines the track from each of the tracks on which data is recorded, based on the logical sector designated by the recording command and the track information. .

In step S1702, the driving device 520 determines whether the logical sector designated by the write command corresponds to a recorded physical sector or an unrecorded physical sector. In this check, the drive device 520 determines the state of the physical sector using the logical sector commanded for writing by the controller 511. If the logical sector number is less than NWA, the physical sector is recorded, otherwise it is not recorded. If the logical sector specified by the write command corresponds to a physical sector that has not been recorded, the process proceeds to step S1703; otherwise, the process proceeds to step S1704 if the logical sector corresponds to the recorded physical sector.

In step S1703, the driving device 520 records data into an unrecorded physical sector corresponding to the logical sector in advance.

In step S1704, the drive device 520 records data in the physical sector indicated by the next recordable address in the track determined in step S1701. When data is remapped based on an ECC block, the other unrecorded physical sector is one of the sectors belonging to the next recordable block, the ECC block. For example, if the ECC block consists of 32 sectors, the second sector in the ECC block is instructed to overwrite the second sector in the ECC block, and the data is physically transferred to the second sector in the next recordable ECC block. Is recorded. Thus, the relative address within the ECC block is maintained for the remapped ECC block.

In step S1705, the driving device 520 generates a remapping table including remapping information for remapping the original address of the physical sector recorded in the remapping address of the physical sector indicated by the next recordable address, Store remapping information in the defect list / remapping table. If the ECC block consists of 32 sectors, the original address is the start address of the ECC block to which the original address belongs and the remapped address is the start address of the ECC block to which the remapped physical sector belongs.

In response to a command from the controller 511 to reserve the track, the process that follows the drive 520 is shown in FIG. 17B.

In operation S1711, the driving device 520 receives an allocation command from the controller 511 and allocates at least one track in response to the allocation command. Allocation of at least one track includes assigning first and second tracks in the track determined in step S1701.

When the present invention is applied to a recording / playback system such as a consumer video recorder or a consumer video player, the controller 511 and the drive device 520 may be controlled by a general microprocessor as shown in FIG. In this case, the controller 511 may not query the NWA to the drive device 520 because the recording / reproducing system knows the NWA. First, the NWA in each track is checked when the disc is loaded into the drive unit, and then the system can manage the NWA after some data has been recorded.

18 shows an optical disc information recording / reproducing system 1800 that is part of a consumer video recorder or consumer video player. The information recording / reproducing system 1800 includes a controller 1811, a memory 1812, and a driving mechanism 1800 for reading and writing information from the optical disc. The controller 1811 can be, for example, a semiconductor integrated circuit such as a CPU (central processing unit) and performs the method described in embodiments of the present invention. Moreover, a program is stored in the memory 1812 that causes the controller 1811 to perform the method described in the above embodiments. At the controller 1811, a file system, utility program, or device driver may be performed. The drive mechanism 523 can be controlled by the controller 1811.

FIG. 19 is a flowchart illustrating a process for recording data on a write-once optical disc by the recording / reproducing system described in FIG. 18.

In step S1901, the controller 1811 receives a request from the user. For example, the request may be to replace Data-A with new data or to copy Data-B from another medium on the disk to the root directory. The data to be recorded is transferred to the memory 1812 and the destination for recording the data is indicated by a path name in the directory tree structure.

In step S1902, the file system instructs the driving device to read the data which is the metadata file FE for recognizing the area allocated for the metadata file and the metadata mirror file.

In step S1903, the file system instructs the drive device to obtain track information.

In step S1904, the file system checks each track to see if the track is used for metadata recording. If a portion of the track is specified in the size of the metadata file or the metadata mirror file, the track is used to record the metadata into the metadata file or the metadata mirror file respectively.

In step S1905, the file system reads data to retrieve a directory or file requested by the user. Metadata such as file entries and directories are read from the metadata file.

In step S1906, the file system takes the NWA before recording the data.

In step S1907, the file system checks whether each track is used. If the track for metadata recording is exhausted, the flow goes to step S1908.

In step S1908, the file system designates a new track as a track reserved in the track used for data recording.

In step S1909, in response to the user request, the file system generates a portion of the metadata so that the amount of data to be overwritten is minimized by distinguishing the type of data to be recorded. As described in the description of FIG. 11, when the file is updated, the file system creates a file entry to specify the location of the data to be recorded. This file entry is the data to be overwritten. When a new file is written under a directory, the file system creates a file entry of the new file and updates the directory to register the new file and file entry of the directory. File entries in a directory are data that will be overwritten and other data that can be written without being overwritten. Data types are divided into type I, which does not need to be overwritten, and type II, which needs to be overwritten.

In step S1910, the file system instructs to write type I data from the NWA to the logical sector. Subsequently, the process goes to step S1911 which is an operation for recording data without overwriting.

In step S1912, the file system instructs to overwrite the type II data with the logical sectors. Subsequently, step S1913 is performed to perform an operation for writing data in the logical sector. The write commands ordered to write the data may be different for Type I and II.

In step S1913, the data is logically overwritten in a logical sector and physically recorded in another unrecorded physical sector, in particular in NWA.

In step S1914, the entry as the remapping information is generated to specify in advance the principle address of the physical sector corresponding to the logical sector and to specify the remapping address of the physical sector in which data is recorded, and is stored in the defect list.

In step S1915, the file system checks whether the allocated area is expanded as the size of the metadata file and the metadata mirror file. If this area is expanded, the flow goes to step S1916.

In step S1916, the file system changes the file entries of the metadata file and the metadata mirror file to designate an area in which the file entry is extended, and instructs the driving device to write the file entry in the logical sector read in step S1902.

Hereinafter, the reproduction process from the one-time recording disc in which data is recorded using the method described above in Figs. 16, 17A, 17B and 19 is described. 20 is a flowchart illustrating a process of reading data from a write-once optical disc by the recording / reproducing system described in FIGS. 5 and 18. In Fig. 20, the recording / reproducing system receives a read command specifying at least a logical sector from which data is read.

In step S2001, original addresses of all entries stored in the remapping table are retrieved. If the number of logical sectors to be read is indicated, the physical sector number corresponding to the logical sector in advance is used to retrieve an entry indicating that the physical sector is to be remapped. When remapping is performed on an ECC block basis, it is checked whether the number of physical sectors belongs to the remapped ECC block. This operation can be performed by the driving apparatus in the case of the information recording / reproducing system as described in FIG.

In step S2002, if the entry is found, go to step S2003, otherwise go to step S2004.

In step S2003, the original address of the physical sector is replaced with the remapping address of the physical sector, which is indicated in the found entry. If the entry is not found in step S2002, the address to be read is determined as the address of the physical sector corresponding to the logical sector specified by the read command. If the entry is found in step S2002, the address to be read is determined as the remapping address corresponding to the original address found in the remapping table.

In step S2004, the data is read at the determined address.

As described above, when the address is not found, data is read from the physical sector corresponding to the logical sector in advance, since the remapping table shows that the data stored in the logical sector is not remapped to another physical sector. to be.

When no address is found, the data is read from the physical sector specified by the remapping address in the found remapping information, because the entry found in the remapping table shows that the data stored in the logical sector is remapped. .

If data is remapped in volume space, especially if it is remapped to an NWA in a track rather than in an extra area, the data can be read more quickly.

As described in the above-described embodiment, the present invention is directed to minimizing the amount of data that is overwritten when the data is written without overwriting the sector and to the unwritten sector by querying the drive device. Applied to the drive device under the assumption of commanding to write data.

(Example 4)

In this embodiment, as an example, guidelines and requirements for executing the UDF file system are described.

(Advantages of using the pseudo-overwrite method)

In order to reduce the complexity due to physical features, new sequential recording media with overwriteable features are introduced as pseudo-overwriteable media. The pseudo-overwrite method applies to this pseudo-overwriteable medium. Next, some of the advantages of introducing a new sequential recording medium will be described.

1) Similar to rewritable media, overwriteable volume space and defective free space are provided. In other words, compatibility with the write-once medium is ensured by the drive device supporting the overwritable mechanism and the defect management.

2) Session closure and border closure are unnecessary, such as when a read only drive supporting pseudo-overwrite media accesses an unwritten area.

3) Metadata partitions and their mirrors can be used.

(Characteristic of pseudo-writable media)

The physical characteristics of the pseudo-overwriteable media are described from the perspective required by the file system driver.

Pseudo-overwritable media supports multi-track write and overwrite capabilities for logical sectors in volume space. More than one track can be used for recording. A new track can be designated as a reserved track. Sequential recording mode is used within the track to simplify space management. The pointer to the recordable area is the next recordable address NWA, which is obtained through the request of the driving apparatus.

When data is to be recorded on the recorded logical sector, this data is written to the NWA in the spare area or in the volume space by a linear replacement algorithm. As an advantage of remapping data to NWAs in volume space, all available media volumes can be used, even when all of the spare area is written. Therefore, a read modifier write operation is also supported, and each logical sector can be overwritten separately.

Address information for which data is replaced or remapped from the original address is stored as a defect list entry from the volume space and managed by the drive device.

(Writing strategy by file system)

In general, a track may be designated by considering the type of data to be recorded, for example, specific data such as metadata or audio / visual data, still image data, music data, and the like. In multi-track recording, when a reserved track is depleted, a new track is designated, adapted to the amount of recorded data. The track for metadata recording is externally represented as the size of the metadata file or metadata mirror file.

If the pseudo-overwrite medium has a limitation that no new track can be specified after the track is specified at the end of the volume space, multi-track recording is used in the intermediate state where only one AVDP is written to LSN 256. In accordance with ECMA 167 requirements, the AVDP is recorded in at least two or three positions (ie LSN 256, LSN-256 and the last LSN). In this example the track is designated to record the AVDP at the last LSN-256 or the last LSN.

Metadata mirror files can also be used. It is recommended to create a metadata mirror file when the disk is used for recording. In the case of online use, even if the offset of the NWA in each track is not the same due to the recording conditions of each track, the content recorded in the metadata file and the metadata mirror file is recorded to have the same offset in each file. Is done.

21A shows an example of track layout after logical format. First, a volume structure including the AVDP of LSN 256 and its associated file structure is recorded. Then, one track is designated in the metadata recording, and the metadata is recorded in that track. The remaining area in the volume space is used for recording file data.

21B shows an example of the track layout after some files are recorded. After the first track is exhausted, a new track is designated. Thus, additional tracks can be designated in turn.

21C shows another example of the track layout after some files are recorded. When a track for metadata recording is depleted, an additional area for the metadata file can be assigned to the data track as an extension rather than a track.

(Requirements for File System)

The requirements for the pseudo-overwrite method are listed as follows.

1) A query to the drive device is performed to recognize a pseudo-overwriteable medium.

2) Unallocated spatial bitmaps and unallocated spatial tables are not recorded.

3) The metadata bitmap file is not recorded.

4) Inquiries about the NWA of each track should always be performed prior to additional data recording. If a write command appears in an already-recorded area, a defect list entry is used. Therefore, this requirement is important for reducing unnecessary defect list entries since the size of the defect list is limited.

5) The erased block should not be reused to query the NWA for the same reason.

6) Overwritten metadata should be minimized. It is recommended that only directory file entries be overwritten.

 The present invention is useful for providing a recording method for a write-once type disc and a semiconductor integrated circuit for use in a recording device or a reproducing device using a logically overwriteable mechanism.

Claims (12)

A recording method for instructing a drive device having a pseudo-overwrite function to write data on a write once disc, wherein the write once disc comprises a volume space including a plurality of tracks. And wherein the pseudo-overwrite function causes the drive device to record the data in the unrecorded area in response to a command to record the data into the already recorded area by a replacement operation: (a) receiving a write request specifying data for a file to be written; (b) instructing the drive device to read a file entry of the metadata file that includes metadata for managing the file from the location of the write-once disc, to obtain a file entry of the metadata file. step; (c) acquiring track information indicating a position of each of the plurality of tracks; (d) determining, from the plurality of tracks, a track to which metadata is next recorded based on the file entry of the metadata file and the track information; (e) instructing the drive device to read the metadata from the position of the write-once disc to obtain the metadata; (f) obtaining a next recordable address indicating a position at which data is next recorded in a track other than the track determined in step (d), wherein the track is selected from the plurality of tracks. step; (g) updating the metadata to reflect a record of the data specified by the record request; (h) instructing the drive device to record the data designated by the write request at a location indicated by the next recordable address in the write-once disc; And (i) instructing the drive device to record at least some of the updated metadata at the location where the metadata is read in the write-once disc in step (e); Determining whether the next recordable address in the track determined in step (d) is valid; And When it is determined that the next recordable address in the track determined in step (d) is invalid, instructing the drive device to allocate a first track whose metadata is next recorded and a second track where data is next recorded. And updating the next recordable address obtained in step (f) to a next recordable address in the second track. delete delete delete A system controller for instructing a drive device having a pseudo-overwrite function to write data on a write once disc, wherein the write once disc includes a volume space including a plurality of tracks, and the pseudo-overwrite function. In the system controller, the write function causes the drive device to write the data to the unrecorded area in response to a command to write data to the area already recorded by the replacement operation: The system controller includes a controller for controlling the drive device, Wherein said controller is configured to perform a process comprising the steps of the recording method according to claim 1. The method of claim 5, The controller is a semiconductor integrated circuit. A computer-readable storage medium for storing a program for use in a system controller instructing a drive device having a pseudo-overwrite function to write data on a write-once disc, wherein the write-once disc is a plurality of tracks. And a pseudo-overwrite function, wherein the pseudo-overwrite function causes the drive device to write the data to the unrecorded area in response to a command to record the data to the already recorded area by a replacement operation, In the computer readable storage medium: And wherein the program is configured to, when executed by the system controller, cause the system controller to perform a process comprising the steps of the recording method according to claim 1. delete delete delete delete delete

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